NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Antoine Couëtte
Date: 2011 Jan 4, 23:05 -0800
RE : http://www.fer3.com/arc/m2.aspx?i=115158
[NavList] Daytime Jupiter Ex-Meridian/ M.P. /LOP Exercise
From: gregrudzinski---com
Date: 4 Jan 2011 19:02
Dear Greg,
Welcome to the "JDTLS Club" (Jupiter Day-Time LAN Shooters Club) !
Number crunching your data - using just LAN Software this time - yields :
UT of Jupiter Transit (i.e. Jupiter due South of Observer) : 00h50m50.7 s, and
UT of Jupiter Culmination : 00h50m52.4s , and
Observer's position at Transit Time : N34°10'6 W119°08'6
and - again - you had a very good SD for all these observations : 0.2 NM (whaooo !!! sharpshooter )
Still, the results accuracy remains average because - while the "permissible" Time-Span of the observations around Culmination Time is rather important here - the "actual" Time-Span is quite reduced : less than 10 minutes of time before Culmination and less than 2 minutes of time after Culmination.
As regards "permissible" Time-Span, my results show that in this specific example, Jupiter can be observed during a Time-Span of +/- 46 min of time around observed Culmination Time without inducing/bringing any additional appreciable uncertainty ( i.e. to the 0.1' level) due to the computation method used here.
As a consequence, the ratio between the uncertainty in the heights measurements and the quite small overall amplitude of the heights (4.1' between highest and lowest ones) is not in our favour here, especially because we are in a LAN environment.
While I understand that this exercise might essentially be rather an Ex-Meridian exercise, I think it is also worth being treated as a LAN, just to see and interpret its results.
Would it then be feasible for some next opportunity to also include observations taken at times more distant from the Culmination Time (up to 40 minutes either side if a similar environment) ?
Thank you very much again, and Thanks in advance also :-) !
Best Regards
Kermit
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